The mental abilities of a user of a vehicle, such as of a driver of an automobile, is an important factor in the safety of automotive travel. Particularly, the state of mind, or the cognitive state, of the user plays an important role in the safety of the user and others while the user operates the vehicle.
Persons suffering from mental illnesses, suffering from illnesses having adverse mental or cognitive consequences, operating under stress, operating under the influence of medication or toxins, or afflicted with age related decline of mental capabilities are some examples of individuals with diminished cognitive abilities. While operating a vehicle is prohibited for persons suffering from some types of diminished cognitive abilities, individuals with other types of diminished cognitive abilities can and do legally operate vehicles for their day-to-day needs.